Answer:
 π = C/(2r)
Step-by-step explanation:
The equation that relates the circumference of a circle to the radius is ...
 C = 2πr
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We can divide both sides of the equation by 2r to get an expression for π.
 [tex]C=2\pi r\\\\\dfrac{C}{2r}=\dfrac{2\pi r}{2r}\\\\\boxed{\pi=\dfrac{C}{2r}}[/tex]